Pets actually do get buffs from supply drops if they understand to walk on it. I noticed it long time ago with backup trinket. You could of course force your pet to walk on it by resummoning her onto supply drop or trying to drop supply drop on her feet but I know it is little tricky. Other trinkets dont buff pets but developers said that weapon attacks are big part of the AM also thinking about the power regeneration and other trinkets still buff your weapon combos.
